Water management

Cloudburst adaptation

Jonathan A. Leonardsen
Jonathan A. Leonardsen
October 23, 2019

Overcoming the financial obstacles, harvesting the benefits of nature-based solutions

Cloudburst adaptation of Skt. Kjelds plads

The world’s population is mainly located in or around urban, built-up areas. A trend that has resulted in dense cities with a lot of impermeable surfaces and a loss of natural land and ecosystems. It is a trend that also places billions of people around the world at risk. Our current climate poses serious challenges to our urban way of living. Stormwater floods, cloudbursts, droughts, heat waves, and the like occur more frequently around the world.

Combine the current climate risk with rapid urban population growth, particularly in the Global South, and climate change trends and our urban way of life could be gravely challenged. Even if we stay on the 1.5-degree track, we are likely to see costs from flooding surpass the $10 trillion mark according to a report by the Global Commission on Adaptation. Moreover, millions of people are at risk in our urban communities. In the following piece, I will look more closely at cloudburst adaptation in cities, the structural obstacles to adaptation, and the benefits of nature-based solutions. The lessons learned can, however, easily be transferred to other adaptation and resilience aspects of urban development.

Obstacles – water doesn’t care about regulations

One of the great obstacles for cities when tackling cloudburst adaptation, is the fact that the costs are uncertain. They may be lower than we expect, but they may very well be a lot higher too.. Cloudburst adaptation often becomes an exercise of economic prioritisation, a very expensive insurance policy that might not pay out.

Another challenge is the fact that our cities and nations are governed in a silo approach. Often, the task of cloudburst adaptation falls on e.g. the utility company that handles stormwater runoff. However, the solutions for cloudburst adaptation are not limited to the functions of the utility company.

Water, as opposed to most people, does not respect regulatory and institutional boundaries. Rather, it flows and gathers based on the design of the urban landscape and topography.

Ideally, the responsibility of dealing with adaptation is not placed in one city agency, but becomes a policy and design guideline for all agencies to follow; e.g. the parks will adopt an approach to increase blue-green infrastructure, the schools will handle water in school yards (where feasible) and the roads will be designed as conveyors of water as cloudburst boulevards, etc.

If cloudburst adaptation is an insurance policy – how do we get it to pay out?

Looking closer at nature-based solutions and the impacts of urban nature, the benefits are clear and well documented including an increase in the number of visitors and time spent in these areas. This results in physical and mental health benefits, it impacts the local community with increased sales and revenue in the food and beverage sector (as well as local shops). Nature-based solutions impact the bio diversity and often increase it dramatically, reducing air and noise pollution and much more – talk about a pay-out!

Financing = obstacle

However, financing is still an obstacle. Although the ideal scenario is the adoption of citywide policy and guidelines for cloudburst adaptation, this is rarely the case. More often we come across situations where co-financing solutions across city budgets are near to impossible. People do tend to care about regulations.

If people care about regulations and water doesn’t, is all lost?

The examples that we have of co-financing nature-based solutions, show us that all is definitely not lost! In Singapore, a 50 ha. park and a 3.2 km long concrete canal were situated next to each other, but not connected. After a remodelling (cheaper than a refurbishment of the concrete canal) the new nature-based solution sported a 60 ha. park complete with a meandering waterway and a resulting 100 % increase in park users.


Use the arrows to see the park before and after

The city’s utility company (PUB) and parks services (NPARKS) saw an opportunity for both parties to gain by combining their budgets and efforts. The concrete canal needed refurbishment. It did not have sufficient capacity for future needs, and moreover, it acted as a barrier for the residential area to the park.

Together the two agencies worked to create a nature-based solution with a natural waterway, sloping banks and vegetation. It created a blue-green zone, where nature has been able to flourish and biodiversity has increased, bringing back dragonflies, fish and even river otters to the area. And the hydrological capacity has been increased to handle cloudburst events of the future.

Bishan Ang-Mo Kio Park is a great example of what cities can create when their agencies understand that co-benefits of one agency’s project can be a direct win to another agency.

But what about cities who need cloudburst adaptation solutions but do not happen to have a park and a waterway conveniently located next to each other?

In Copenhagen, a roundabout has been transformed from a traffic installation to a social meeting place, a lush nature-based urban adaptation solution.


Use the arrows to see the area before and after

Two thirds of the impermeable area (9.000m2 of asphalt) has been replaced by almost 600 new trees, 3.000m2 perennials, and 500 m2 wild grass transforming the urban landscape into a hospitable and inviting location, with new cafes opening and expanding their outdoor services.

Next steps – where can we go from here?

Cities that wish to act on the current challenges facing us in terms of cloudbursts and extreme rain events need to think and design solutions in an integrated manner – that much is clear. The integration and co-creation require that the different agencies design the adaptation policies together, that the agencies set aside their own current regulatory limitations and identify the optimal solution to the local problems. In Copenhagen there was a need to change the financial mechanisms for the utility company to co-finance the nature-based solutions, which required a change in the national legislation.

Cities are at the forefront of the battle against climate change and will suffer the consequences. Cities have moved from being followers of a national agenda, to becoming leaders of the international agenda. Therefore, cities can overcome the financial obstacle of working across city budgets and utilise the full range of benefits from nature-based solutions for urban cloudburst adaptation, when they work together to identify the multiple and overlapping benefits that will serve the different city agencies and the stakeholders of the city – developers, citizens, local business, etc.

Singapore and Copenhagen are luckily just two examples out of many, demonstrating that it is possible to overcome the obstacles. That’s why I urge all urban adaptation officials to reach out to the city networks and to learn and collaborate with other cities to overcome the challenges. Let’s harvest the benefits of urban climate adaptation!

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